1. Field of the Invention
This invention is directed to two-way optical-electrical communication systems.
2. Description of the Prior Art Optical Communication Systems
Conventionally, two-way communication via an optical communication system has been accomplished either with two parallel links propagating signals in opposite directions, or with a single link employing a transmitter and a separate detector at each end and a means for separating the received signals from the transmitted signals at each end. The latter means may comprise, for example, a beam splitter mirror which partially transmits and partially reflects light off to the side.
Optical detectors for such prior art optical communication systems include such solid state semiconductor devices as p-n-p photo transistors, p-i-n photodetectors, avalanche photo diodes, Schottky-barrier devices and silicon p-n junction photo cells.